Bidirectional Mappings for Data and Update Exchange
Grigoris Karvounarakis, Zachary G. Ives

Abstract
A key challenge in supporting information interchange is not only
supporting queries over integrated data, but also updates.
Previous work on update exchange has enabled update propagation
over schema mappings in a unidirectional way --- conceptually
similar to view maintenance, in that a derived instance gets
updated based on changes to a source instance.
In this paper, we consider how to support data and update
propagation across bidirectional mappings that enable
different sites to mirror each other's data.  We show how data and
update exchange can be extended to support bidirectional updates,
implement an algorithm to perform side-effect-free update
propagation in this model, and show preliminary results suggesting
our approach is feasible.